1. Field of the Invention
The present invention is directed to a polarized electromagnetic relay, and more particularly to a polarized miniature electromagnetic relay with a reduced height.
2. Description of the prior art
Polarized electromagnetic relays have been widely utilized in the art. As disclosed in German Pat. No. 2148377, and U.S. Pat. Nos. 2,960,583, 4,064,471, and 4,695,813, typical prior art polarized electromagnetic relays are generally designed to comprise an electromagnet with a magnetic core and an excitation coil, an armature carrying a movable contact, and a permanent magnet for polarity responsive armature movement. In order to provide a compact arrangement for these three major parts of occupying relatively large spaces in the relay structure, i.e., the electromagnet, the armature, and the permanent magnet, the armature is mounted to extend along generally in parallel with an axis of the excitation coil of the electromagnet within the length of the electromagnet and is pivotally supported for contacting operations about a pivot axis which is perpendicular to the axis of the excitation coil. Also the permanent magnet is disposed between the armature and the electromagnet to magnetically couple them for the polarity responsive armature actuation. When the armature is required to have its pivot axis horizontally to meet with a particular contact arrangement demanded for the relay structure, the electromagnet, the armature and the permanent magnet are arranged to be vertically stacked, as seen in the above U.S. Patents. Consequently, the relay has to be made with an increased height as much as the added vertical dimensions of at least the electromagnet and the armature. In this respect, the prior relays fails to be miniaturized with respect to the height dimension.
Further, in the relay particularly of miniaturized ones, it is highly desired to electrically separate the electromagnet and the armature as much as possible within a limited space in order to give enough insulation distance between the excitation coil and a set of contacts provided on and adjacent to the armature. However, the prior art relays with vertically stacked electromagnet and the armature are found difficult to provide effective electrical insulation between the excitation coil of the electromagnet and the set of contacts on the side of the armature.